Monopropellants



3,031,838 MONOPROPELLANTS .Richard C. Doss, Bartlesville, kla., assignor to Phillips Petroleum Company, a corporation of Delaware No Drawing. Filed Mar. 10, 1958, Ser. No. 720,498 16 Claims. (Cl. 60--35.4)

This invention relates to novel two-component monopropellant compositions suitable for use in rocket motors, ram-jets, pulse-jets and the like. In a further aspect, this invention relates to a method of operating such motors.

Rocket motors are operated by burning a mixture of fuel and oxidant in a combustion chamber and causing the resulting gases to be expelled through a nozzle at high velocity. Liquid propellants are preferred over solid propellants where it is necessary to vary thrust during flight. Liquid propellants are classified as bipropellants and monopropellants, and the latter are either a single compound or mixtures of compounds. Monopropellant systems are advantageous in that they require only one tank, one pump, one nozzle, on fuel line, one set of controls, etc. Furthermore, no mixing or proportioning system is required.

The principal elements of a rocket motor utilizing a liquid fuel comprise a combustion chamber, exhaust nozzle, an injection system, and propellant control valves. The propellent gases are produced in the combustion chamber at pressures governed by the chemical characteristics of the propellant, its rate of consumption, and the cross-sectional area of the nozzle throat. The gases are ejected into the atmosphere through the nozzle with supersonic velocity. The function of the nozzle is to convert the pressure of the propellent gases into kinetic energy. The reaction of the discharge of the propellent gases constitute the thrust developed by the rocket motor.

The following are objects of this invention.

An object of this invention is to provide a novel twocomponent monopropellant combination. Afurther object of this invention is to provide a method for operating rocket motors. V

Other aspects, objects, and advantages of this invention will be apparent to one skilled in the art upon reading this disclosure.

In accordance with the invention there are provided novel two-component monopropellent compositions, suitable for use according to the method of the invention in rocket motors and the like. Broadly speaking, the invention comprises the use of an amine perchlorate and a suitable oxidant as a two-component monopropellant.

Thus according to the invention there is provided a two-component monopropellant comprising a mixture of (1) an oxidant and(2) an amine perchlorate selected from the group consisting of'piperidine perchlorate, pyridine perchlorate and amine perchlorates characterized by a formula selected from the group consisting of wherein: each R is selected from the group consisting 3,031,838 Patented May 1, 1962 of acyclic, alicyclic, and aromatic hydrocarbon radicals containing from 1 to 8 carbon atoms, and hydrogen; and R is selected from the group consisting of (a) alkylene, alkenylene, and alkynylene hydrocarbon radicals containing from 1 to 8 carbon atoms, and

TRa-x R -radicals wherein each R is an alkylene radical containing from 1 to 4 carbon atoms, and X is selected from the group consisting of oxygen, sulfur, and

radicals wherein R is defined as above, y is an integer of from 1 to 3, z is an integer of from 1 to 3, and n is an integer from 1 to 5;

the total number of carbon atoms in the molecule does not exceed 40, and the total number of amino nitrogen atoms in the molecule does not exceed 10.

The terminology amine perchlorates is intended to include perchlorates of monoamines, diamines and higher polyamines. The amine perchlorate can be perchlorates of primary, secondary, and tertiary amines. Examples of amine perchlorates suitable for use in the practice of the invention include, among others, the following:

N,N'-dimethylaniline perchlorate;

triphenylamine perchlorate;

N,N-di-n-octyl-p-tolylamine perchlorate;

alpha-methylbenzylamine perchlorate;

diisopropylamine perchlorate;

N,N,N, '-tetramethylethane-1,2-diamine diperchlorate;

N,N,N',N-tetramethylpropane-1,2-diamine diperchlorate;

N,N,N,N-tetramethylbutane-1,B-diamine diperchlorate;

ethane-1,2-diamine diperchlorate;

N,N,N',N-tetramethyl-2-butyne-l,4-diarnine diperchlorate;

N,N,N',N'-tetraethylethane-1,2-diamine diperchlorate;

N,N,N',N-tetrarnethylbutane-l,4-diarnine diperchlorate;

N,N,N,N-tetrarnethyloctene-4,8-diamine diperchlorate;

N-phenyl-N'-n-octylethane-1,2-diarnine monoperchlorate;

N,N,N,N'-tetra-n-octyloctane-1,2-diamine diperchlorate;

N,N,N,N'-tetracyclohexylhexane-2,5-diarnine diperchlorate;

N,N-di-p-tolylpropane-1,3-diarnine monoperchlorate;

N-alpha-methylbenzyl-Z-butene-1 ,4diamine monoperchlorate;

N,N'-dicyclohexenylethane-1,2-diamine diperchlorate;

N,N,N,N-tetramethyl-2-butene-1,4-diarnine diperchlorate;

N,N,N,N'-tetraethylpropane-1,B-diamine diperchlorate;

N-2,4-dimethylcyclohexyl-N'-n-octy1-n-octane-1 ,8-

diarnine diperchlorate;

N-n-propylpropargylamine perchlorate;

N,N-di(2-butynyl)propane-1,3-diamine diperchlorate;

N,N,N,N-tetrapropargylbutene-1,4-diamine diperchlorate;

N-Z-butynyl-N-propyl-2-butene-1,4-diamine monoperchlorate;

bis (N-rnethyl-N-propargylaminoethyl) thioether diperchlorate;

N,N,N-tri(2-butynyl)diethylenetriamine triperchlorate;

N,N,N,N-tetra(2-pentenyl)hexane-1,6-diamine diperchlor-ate;

N,N,N,N-tetra(3-octenyl) octane-1,7-diarnine diperchlorate;

1,4-diamino-2-butene diperchlorate;

N,N,N,N'-tetraphenyl-n-3-octene-1,3-diamine diperchlorate;

N,N-di(2-ethylhexyl) -2-butene-1,4-diamine monoperchlorate; I

N,N,N-tri-n-propeny1-Z-butene 1,3 diamine diperchlorate;

N'-cyclohexyl-N-cyclohexenylpropane-1,3-diamine m'onoperchlorate;

N,N,N,N-tetraethyl-4-octyne-1,8-diamine dipherchlorate;

N,N'-dimethylethylene-l,2-dian1ine diperchlorate;

N,N-di(2,4-dirnethylphenyl)-2-butyne-1,4-diamine monoperchlorate;

N,N-dicyclohexyl-Z-pentyne-1,S-diamine diperchlorate;

N,N,N-tri-n-butenyl-2butyne-1,4-diamine monoperchlorate;

bis-(N,N-dirnethylaminoethy1-) ether diperchlorate;

bis N,N-di-n-octylamino-n-butyl) ether .monoperchlorate;

N-cyclohexylaminopropyl N-phenylaminopropyl ether diperchlorate;

N- (Z-ethylphenyl) aminoethyl, amino-n-butyl ether diperchlorate;

bis(arnino-n-butyl) ether diperchlorate;

bis (N,N-di- Z-ethylcyclohexyl] amino-n-buty1) thioether diperchlorate;

bis(aminoethyl) thioether monoperchlorate;

bis(N,N-dimethylaminoethyl) thioether-diperchlorate;

N,N,N,N-tetramethyl-l,3rdiarnino-2-propanol diperchlorate;

4 N,N,N',N-tetraethyl-1,3-diamino-2-propanol diperchlorate; N,N-diphenyl-l,9-diarnino-5-nonanol monoperchlorate; N,N',N-tri-2-ethylcyclohexy1-1,4-diarnino-2-butanol diperchlorate; N,N-di-(2,4-dirnethylpheny1)-1,3-diamino-2-propanol rnonoperchlorate; N,N-dicyclohexenyl-1,4-diamino-2-butanol diperchlorate; N,N,N,N-tetra-n-propenyl-1,6-diamino-3-hexano1 monoperchlorate; N,N-dimethylethane-1,Z-diamine diperchlorate; N,N,N,N,N"-pentamethyldiethylenetriamine triperchlorate; N,N,N"-tricyclohexyldiethylenetriamine diperchlorate; N,N,N,N',N"-pentaphenyldibutylenetriamine triperchlorate; N,N-di-p-tolyldipropylenetriamine monoperchlorate; N,N,N-tri-n-octyldiethylenetriamine triperchlorate; N,N,N',N,N"-penta-2-ethylbutyldiethylene triamine diperchlorate; N,N",N"-tri-2-ethylcyclohexenyldiethylene triarnine triperchlorate; diethylenetriamine triperchlorate; N,N',N',N",N",N" hexarnethylpropane-1,2,3-triamine triperchlorate; N,N,N",N"tetra(Z-ethylphenyl)butane-l,2,3,4-

tetrarnine diperchlorate; N,N-di(2,4-dimethylcyclohexyl)pentane-1,3,5-triamine triperchlorate; N,N,N',N',N",N"-hexa-2-butenylpropane-1,2,3-triarnine monoperchlorate; propane-1,2,3-triamine triperchlorate; N ,N ,N N ,N ,N ,N ,N ,N ,N -decarnethylpentanel,2,3,4,5-pentamine pentaperchlorate; 'N ,N ,N ,N ,N pentaethyltetraethylenepentamine triperchlorate; N,N,N;N-tetra-n-propyl-2,4-6-trihydroxyheptane-1,7-

diamine diperchlorate; N,N,N,N-tetramethyl-3,6-dioxaoctanel ,8-diamine diperchlorate, and 2,4,6-trithiaheptane-1,7-diarnine monoperchlorate, and 1,2,3,4,6',7,8,10,11,12-deca-(N-methy1amino)dodecane pentaperchlorate.

As shown by the listing of the above specific compounds, the amine, perchlorates of the monopropellants of this invention can, be monoperchlorates, diperchlorates, or polyperchlorates, depending upon the amine employed and the amount of perchloric acid employed, as will be shown, hereinafter. In addition, it is also shown by the above specific, compounds that the amine perchlorates of this invention can be perchlorates of amines which contain elements other than carbon, hydrogen and nitrogen.

The amine perchlorates described above are oxygen deficient and consequently the fuel compositions of my invention require an oxidant. Suitable oxidants that can be used in the two-component monopropellantcompositions includeanhydrous nitric acid, nitric acid (red and white fuming), hydrogen peroxide, and theliquid nitro substituted aliphatic hydrocarbons such as nitro methane, dinitromethane, trinitrornethane, tetranitrornethane, nitroethane, dinitroethane, trinitroethane, pentanitropropane, and. the like.

Nitric acid is the presently preferred oxidant for use in the practice of the invention. Since water tends to retard combustion of the acid with the fuel, the nitric acid is preferably substantially free of water. Thus, the presently most preferred oxidant is anhydrous nitric used in the practice of the invention. White fuming nitric acids and red fuming nitric acids of varying 'con-' centrations are available commercially, and all are useful in the practice of this invention. White fuming nitric acid usually contains about 90'to '99 weight percent HNO from to 2 weight percent N0 and up to about weight percent water. Red fuming nitric acid usually contains about 70 to 90 Weight percent I-I NO from 2 to 25 weight percent N0 and up to about 10 weight percent water. scribed acids can be employed to give an acid having any intermediate composition, and all are useful in the practice of this invention. Thus, it has been found that nitric acids of all types containing at least about 70 weight percent HNO are useful as an oxidant in the practice of the invention.

The monopropellants used in the present invention will be preferably near stoichiometric mixtures of oxidant and amine perchlorate. The ratio of fuel component to oxidant can be in the range of 0.75 to 1.25 times that of the stoichiometric amount. A slightly fuel-rich mixture is usually required to give an optimum rocket motor performance. As used herein, stoichiometric ratio is that ratio of fuel to oxidant calculated by assuming complete combustion to N H 0, and CO The normally preferred procedure for preparing the monopropellants of the invention is to admix the amine perchlorate, prepared by any suitable method, with nitric acid or another suitable oxidant in the desired ratio at some time prior to use. The length of storage prior to use will depend upon the storage stability of the particu-' lar monopropellant composition being employed as will be shown hereinafter.

The amine perchlorate-nitric acid two-component monopropellants of the present invention can be conveniently ignited by contacting a stream ofthe monopropellent with a stream of a hypergol such as pyrrole. Any material which is hypergolic when mixed with nitric acid can be used. Other materials hypergolic with nitric acid such as N,N,N,N'-tetramethylpropane-1,3-diamine; N,N,N',N'-tetramethylpropene-1,3-diamine; furfuryl alcohol; ethylenediamine; etc., can also be used to ignite the two-component monopropellent. These hypergols are. simultaneously injected into the combustion chamber with the two-component monopropellent to ignite the monopropellent. 'After the two-component monopropellent is ignited, the flow of hypergol is stopped. A temperature-sensitive element, a time mechanism or other means can be used to terminate the flow of the hypergol. The other two-component monopropellent compositions of the present invention can be ignited by other means such as, for example, by an electric igniter which, of course, can also'be used for amine perchlorate-nitric acid mixtures. V

The amine perchlorates which are employed in the monopropellants of this invention are preferably prepared by reacting perchloric acid with .the amine by charging the perchloric acid into the amine. .The reaction should be carried out at' a temperature below 20 'C? "The'perchloric"acid-which is employed in this preferred method of preparation can be of a concentration 'o'f'from 20% by weight (aqueous solution) upto con- .me-thods for preparingthe amine perchlorates can be For example, other salts of the i,

employed if desired. amines, hydrochlorides for example, can be prepared Of course, mixtures of the above deand subsequently reacted with a perchlorate such as sodium perchlorate. The amine perchlorates can thus be prepared by a displacement reaction.

EXAMPLE I A number of runs were made in which polyamine compounds were reacted with perchloric acid to form the corresponding amine perchlorates. These runs were carried out in accordance with the method of one of the following procedures.

In one run N,N,N',N-tetramethtylbutane 1,3-diamine (21.6 grams, 0.15 mole) was charged to a 1 liter flask fitted with a stirrer, dropping funnel and thermometer. A 20% aqueous solution of perchloric acid (30 grams, 0.30 mole) was added slowly to the diamine at 15 C. As the addition proceeded, a white precipitate of the monoperchlorate was formed. This precipitate redissolved upon further addition of the acid. After the addition of the 'acid was complete, the mixture was stirred for a few minutes and then poured into 7 times its volume of cold isopropyl alcohol. The white crystals which were separated were filtered, washed with isopropyl alcohol and dried in a vacuum dessicator. An 87% yield of the diperchlorate was obtained, this compound having a melting point of 147.5" C.

In another run 29.5 grams (0.50 mole) ofisopropyl amine was charged to a 3-necked, 500 milliliter, round bottomed flask which was fitted with a stirrer, thermometer and dropping funnel. A 20% aqueous solution of perchloric acid. (53.3 grams, 0.53 mole) was added slowly to the amine while maintaining the contents of the flask at 5 C. After the addition was complete, the mixture was stirred for a few minutes and was then evaporated to dryness on a steam bath. The crystalline residue was washed with anhydrous ether, filtered and I at room temperature.

dried in a vacuum desiccator. After recrystallization from isopropyl alcohol and ether, 96.8% yield of the perchlorate was obtained, this compound having a melting point of 142144 C.

Several other amine perchlorates were prepared by the method of one or the other of the twopreparation procedures given above. The properties of the amine perchlorates prepared in these runs are given below in Table I.

EXAMPLE II The amine perchlorates which were prepared as described in Example I were mixed with anhydrous nitric acid in stoichiometric proportions.

The anhydrous nitric acid employed in these mixtures was prepared by the following procedure. To a 5 liter, 3-necked, round bottomed flask was charged 1.5 liters of white fuming nitric acid (commercial grade-92% HNO 8% water). Fifteen grams of urea was added to the flask, and dry air was bubbled through the mixture at C. for 3 hours or until the presence of nitrogen dioxide as indicated by red coloring was no longer present. The mixture was then cooled to room temperature, and 5 50 milliliters'of concentrated sulfuric acid was added to the flask.' The 3-necked flask was then fitted with a thermometer and a jacketed distillation column which was cooled with water. I-Ieat was gradually applied to the flask while simultaneously bubbling dry -air through the mixture. A 51% yield of essentially arrhydrous nitric acid which distilled at 45-50 was obtained.

The anhydrous nitric acid as prepared above was admixed with the various amine perchloratesof Example Properties of the mixtures are given below in Table I.

Table I Monopropellants Stoichiometric Mixtures With Anhydrous HNO: Molec- Melting Impact No. Compound ular Point, Sensitivity,

Weight C. Inch-Pounds Specific Salt in Freezing Storage Impulse, Mixture, Point, Stability Seconds.

Wt. C. at 200 F., Calculated Percent hours at 20 Atm.

Pressure N N N, N- tetramethylethane- 1 2- dia-mine diperchlorate. 317. 1 228-231 8 51. 2 N,N,N,N-tetraethylethane-1,2-diamine diperchlorate. 373. 3 166-168 40 38. 2 6. N N, l\ N- tetra-n-propylethanc-l,

Z-diamine dipcrchloratc. 429. 4 232-235 100 32.1 N,N,N,N'-tetra-n-butylethane-1,2-

diamine diperchlorate. 485. 5 183-185 100 28. 7 N, N, N, N-tetrarnethylpr0pane-1,3-

diamine diperchlorate. 331. 2 228-230 18 46. 7 N,N,N,N tctramethylhexane 1,6

diamine diperchlorate. 373. 3 158-162 60 38. 2 n-propylamine perchlorate 170-173 22 n-butylarnine perchlorate 173.6 195-197 20 0 di-n-propylamine perchlorat 201.7 263-267 34. 1 di-n-butylarnine perchlorate" 229; 7 267:1:5 28 29. 7 visobntylamine perchlorate. 173. 6 185-189 20 42.0 diisobutylamine perchlorate 229. 7 299 22 29. 7 tert-butylamine perchlorate 173. 6 134-139 24 42.0 i n-amylamine perchlorate..- 187. 6 253-257 30 37. 3 di-n-amylamine perchlorate. 257. 8 245(11) 58 27.1 isoarnylamine perchlorate 187. 6 272-274(d) 30 37. 3 diisoarnylamine perchlorate 257. 8 25 36 27.1 n-hexylamine perchlorate. 201. 7 232-238 28 34. 1 2-ethylhexylamine perchlorate. 229. 7 102-104 29. 8 di-(2-ethylhexyl)amine perchlora 341. 9 117-120 20 23. 0 N,N,N,N tetramcthyldecane 1,10 429. 4 94-90 92 32.1

diamine diperchlorate. N,N,N,N 2,2 hexarnetliylpro- 359. 2 185-156 26 40. 4

pane-LIi-diamine diperchlorate. N,N,N,N tetrarnethylbutene 1,4 345. 2 193-195 12 43. 2

diamine diperchlorate. di-(n-hexybaminc perchlorate 285. 8 245(0) 100 25. 3 E thylamine perchlorate 145. 6 300-302 48 (S2. 2 Isopropylamine perchlorate- 159. 6 287-291 49. 4 Diisopropylarnine perchlorate 201.7 311-315 120 34.1 'lriethylamine perchlorate 201. 6 168-171 120 34. 0 N ,N,N ,N tctramethylbutime 1,3 345. 2 296-298 24 diarnine dipcrchlorate. Diethylamine perchlorate 173 6 315-318 1 Estimated from an Arrhenius type plot of stability determinations made in the same manner at 140 F.

(d) =Melts with decomposition.

EXAMPLE III The burning rate at various pressures was determined for a stoichiometric mixture of anhydrous nitric acid with N',N,N',N' tetramethylbutane-1,3-diamine diperchlorate. The equipment employed for the determination of burning rates consisted of an optical bomb which was designed for the burning of solid propellants. The tests were performed by'placing 2 milliliters of the propellant mixture in an 8 millimeter glass tube and thereafter placing the tube in the bomb. After closing the bomb and pressuring to the desired pressure with nitrogen, the propellant mixture was ignited by means of a short length of Nichrom e resistance wire which was immersed in the surface of the propellant liquid. The time required to burn a finite distance was measured, thus the results are expressed. directly in inches per second. The burning rate test results for this diamine diperchlorate-anhydrous nitric acid mixture are given below.

Burning rate, inches persccond. at 100.p.s.i. 0.088 Burning rate, inchesper second at 200 p.s.i. 0.074 Burning rate, inches per second at 300 p.s.i. 0.054 Burning rate, inches per second at 400 p.s.i. 0.063 Burning rate, inches per second at 600 p.s.i. 0.087

Sensitivity to impact is determined by subjecting a Small quantity of confined explosive to the transmitted shock froma fall weightusually 2 kg.and determining the minimum height'of fall that will cause at least one explosion in ten tests. The tests reported herein were determined by the Picatinny Arsenal method. With the Picatinny Arsenal apparatus the cavity in a steel cup is. filled with the solid or liquid explosive, the cup is covered with a cylindrical brass cover having a slip fit, and a small steel plug is placed on the center of the brass cover. In this test, the falling weight strikes the steel plug.

The values for storage stability at 200 F. given in the above Table I were determined by storing 20 milliliters of the acid salt solution in a 30 milliliter bomb immersed in a constant temperature bath. Bomb pressure was then recorded versus time in the storage bath until rupture of a 109 p.s.i. safety disk in the bomb.

Referring to said Table I it will be noted that certain of the mixtures listed therein are definitely superior with respect to storage stability. Storage stability is presently considered to be the most important property of the monopropellants of the invention because the longer the acid-salt solutions can be stored the more useful said mixtures are. Since the monopropellants of the invention may possibly be used or stored under desert conditions, 200 -F. was chosen as a reasonable maximum temperaturev at which to measure storage stability. It will be noted that the following compounds formed monopropellants which are definitely superior with respect to storage stability.

Table II Number in Table I Compound N,N,N,N tetramethylpropane 1,3- diamine diperchlorate.

n-Propylamine perchlorate.

Isobutylamine perchlorate.

tert-butylamine perchlorate.

Isopropylamine perchlorate.

Diisopropylamine perchlorate.

Triethylaminc perchlorate.

It is'to be noted that the compounds of Table 11 all form monopropellants having a storage stability greater than 30 hours.

It is to be realized that the test at 200 F. is a severe test and the mere fact that some compounds give mixtures which have a low storage stability at 200 F. does not mean that said compounds are not useful in the practice of the invention because, at lower temperatures, mixtures of said compounds with nitric acid do have higher storage stabilities than those shown in Table I and can be used at lower temperatures in those instances where storage stability is of secondary importance.

The above listed mixtures in Table II thus represent a select, superior, group of monopropellants. Other considerations such as availability, etc. will enter into the final choice of the most preferred from said select superior group of monopropellants.

Since many possible embodiments may be made of this invention without departing from the scope thereof, it is to be understood that all matter herein set forth is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. A two-component monopropellant consisting essentially of a mixture of (1) an oxidant selected from the group consisting of nitric acid containing at least about 70 weight percent HNO and liquid lower nitroparaflins, and (2) an amine perchlorate selected from the group consisting of pyridine perchlorate, piperidine perchlorate and amine perchlorates characterized by a formula selected from the group consisting of wherein each R is selected from the group consisting of acyclic, alicyclic, and aromatic hydrocarbon radicals containing from 1 to 8 carbon atoms, and hydrogen; and R is selected from the group consisting of (a) alklyene, alkenylene, and alkynylene hydrocarbon radicals containing from 1 to 8 carmon atoms, and

radicals wherein R is defined as above, y is an integer of from 1 to 3, z is an integar of from 1 to 3, and n is an integer of from 1 to the total number of carbon atoms in the molecule does not exceed 40, and the total number of amino nitrogen atoms in the molecule does not exceed 10; the ratio of said amine nitrate to said oxidant being in the range of 0.75 to 1.25 times that of the stoichiometric amount.

2. The monopropellant of claim 1 wherein said amine perchlorate is N,N,N',N-tetramethylpropaue-1,3-diamine diperchlorate.

3. The monopropellant of claim 1 wherein said amine perchlorate is n-propylamine perchlorate.

4. The monopropellant of claim 1 wherein said amine perchlorate is isobutylaminc perchlorate.

5. The monopropellant of claim 1 wherein said amine perchlorate is tert-butylamine perchlorate.

6. The monopropellant of claim 1 wherein said amine perchlorate is isopropylamine perchlorate.

7. The monopropellant of claim 1 wherein said amine perchlorate is diispropylamine perchlorate.

8. The monopropellant of claim 1 wherein said amine perchlorate is tricthylamine perchlorate.

9. In the method for development of thrust by the combustion of a two-component monopropellant in the combustion chamber of a reaction motor, the step comprising injecting into the said combustion chamber a mixture of (1) an oxidant selected from the group consisting of nitric acid containing at least weight percent HNO and liquid lower nitroparaflins and (2) an amine perchlorate selected from the group consisting of pyridine perchlorate, piperidine perchlorate and amine perchlorates characterized by a formula selected from the group consisting of wherein: each R is selected from the group consisting of acyclic, alicyclic, an aromatic hydrocarbon radicals containing from 1 to 8 carbon atoms, and hydrogen; and R is selected from the group consisting of (a) alkylene, alkenylene, and alkynylene hydrocarbon radicals containing from 1 to 8 carbon atoms, and

radicals where R is defined as above, y is an integer of from 1 to 3. z is an integer of from 1 to 3, and n is an integer of from 1 to 5;

the total number of carbon atoms in the molecule does not exceed 40, and the total number of amino nitrogen atoms in the molecule does not exceed 10.

10. The method of claim 9 wherein said amine perchlorate is N,N,N,N'-tetramethylpropane-1,3-diamine diperchlorate.

11. The method of claim 9 wherein said amine perchlorate is n-propylamine perchlorate.

12. The method of claim 9 wherein said amine perchlorate is isobutylamine perchlorate.

13. The method of claim 9 wherein said amine perchlorate is tert-butylamine perchlorate.

14. The method of claim 9 wherein said amine perchlorate is isopropylamine perchlorate.

15. The method of claim 9 wherein said amine perchlorate is diisopropylamine perchlorate.

16. The method of claim 9 wherein said amine perchlorate is triethylamine perchlorate.

References Cited in the file of this patent UNITED STATES PATENTS 2,406,572 Vogl Aug. 27, 1946 2,406,573 Vogl Aug. 27, 1946 2,774,214 Malina et al. Dec. 18, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,031,838 May 1, 1962 Richard C. Doss appears in the above numbered pat- It is hereby certified that error e Patent should read as ent requiring correction and that the said Letter corrected below Column 9, line "l0 for "carmon" read carbon line 53, for "integar" read integer column 10, line 4, for "diispropylamine" read diisopropylamine line 23, for

"an" read and Signed and sealed this 16th day of October 1962.

(SEAL) Attest:

DAVID L. LADD ERNEST W. SWIDER Commissioner of Patents Attesting Officer 

9. IN THE METHOD FOR DEVELOPMENT OF THRUST BY THE COMBUSTION OF A TWO-COMPONENT MONOPROPELLANT IN THE COMBUSTION CHAMBER OF A REACTION MOTOR, THE STEP COMPRISING INJECTING INTO THE SAID COMBUSTION CHAMBER A MIXTURE OF (1) AN OXIDANT SELECTED FROM THE GROUP CONSISTING OF NITRIC ACID CONTAINING AT LEAST 70 WEIGHT PERCENT HNO3 AND LIQUID LOWER NITROPARAFFINS AND (2) AN AMINE PERCHLORATE SELECTED FROM THE GROUP CONSISTING OF PYRIDINE PERCHLORATE, PIPERIDINE PERCHLORATE AND AMINE PERCHLORATES CHARACTERIZED BY A FORMULA SELECTED FROM THE GROUP CONSISTING OF WHEREIN: EACH R1 IS SELECTED FROM THE GROUP CONSISTING OF ACRYLIC , ALICYCLIC, AN AROMATIC HYDROCARBON RADICALS CONTAINING FROM 1 TO 8 CARBON ATOMS, AND HYDROGEN; AND R2 IS SELECTED FROM THE GROUP CONSISTING OF (A) ALKYLENE, ALKENYLENE, AND ALKYNYLENE HYDROCARBON RADICALS CONTAINING FROM 1 TO 8 CARBON ATOMS, AND (B) FIG-02 WHEREIN EACH R3 IS AN ALKYLENE RADICAL CONTAINING FROM 1 TO 4 CARBONS, AND EACH X IS SELECTED FROM THE GROUP CONSISTING OF OXYGEN, SULFUR, AND 